1. Field of the Invention
The present invention relates to an objective lens driving device for an optical pick-up unit, and more particularly, to an objective lens driving device for an optical pick-up unit having an improved structure to facilitate installation of electrical connections between a control signal source and focusing and tracking coils.
2. Description of the Related Art
Generally, in optical recording/reproducing units using an optical disk, such as a laser disk player, a compact disk player or the like, an optical pick-up unit is installed for irradiating an optical beam onto a disk surface and detecting the optical beam reflected from the disk surface. The optical pick-up unit detects the optical beam reflected from the disk surface in the form of binary signals. For successful reproducing of recorded information, the beam focused onto the optical disk should be precise, and the focused beam should accurately trace the tracks formed on the optical disk. Driving an objective lens to adjust the focus position of the beam in the direction of the optical axis is usually referred to as "focusing", and driving the objective lens to adjust the focus position of the beam in the radial direction in order for the beam to accurately trace the tracks is usually referred to as "tracking". The optical pick-up unit employs devices for driving the objective lens in order to perform both focusing and tracking.
Referring to FIG. 1 which shows a conventional objective lens driving device, a movable supporter 1 carrying an objective lens 2 is supported by elastic suspensions 5 extending from a holder 3 fixed on a base 4. A focusing coil 6 and a tracking coil 7 are installed on the movable supporter 1. Once a control current is fed into the focusing coil 6 or the tracking coil 7, a magnetic field is generated by the focusing coil 6 or the tracking coil 7. This magnetic field interacts with the magnetic field of a permanent magnet 8a and a yoke 8b which are fixed on the base 4, and accordingly, the movable supporter 1 moves vertically or horizontally. The focusing coil 6 and the tracking coil 7 are supplied with a control current via a circuit board 9.
In order to assemble the objective lens driving device having the structure described above, since the circuit board 9 is assembled to the movable supporter 1, and since the leads 5a and 6a from the focusing coil 6 and the tracking coil 7 must be soldered respectively to connection portions of the circuit board 9, there are problems in that the assembly process is difficult and the automatization of the assembly process is difficult as well.